System and method for measuring thrust of a propeller

Abstract

An aircraft powerplant and a method for measuring thrust are described herein. A gas turbine engine has a turbine section for extracting energy from combustion gases and has a shaft mounted to the turbine section for converting the energy into rotary motion. A load cell is coupled to an end of the shaft and positioned to rotate with the shaft. The load cell is configured for generating a measurement indicative of propeller thrust. A propeller is coupled to the load cell and is configured for converting the rotary motion from the shaft and the load cell into the propeller thrust. The propeller thrust can be measured from the load cell as the propeller rotates.

The invention claimed is: 
     
       1. An aircraft powerplant, comprising:
 a gas turbine engine having a turbine section for extracting energy from combustion gases, and having a shaft mounted to the turbine section for converting the energy into rotary motion; 
 a load cell coupled to an end of the shaft and positioned to rotate with the shaft, the load cell configured for generating a measurement indicative of propeller thrust; and 
 a propeller coupled to the load cell and configured for converting the rotary motion from the shaft and the load cell into the propeller thrust. 
 
     
     
       2. The aircraft powerplant of  claim 1 , further comprising a computing device communicatively coupled to the load cell and configured for receiving the measurement and determining the propeller thrust based on the measurement. 
     
     
       3. The aircraft powerplant of  claim 1 , further comprising a rotating electrical connector communicatively coupled between the load cell and the computing device. 
     
     
       4. The aircraft powerplant of  claim 3 , wherein the rotating electrical connector is connected between the load cell and the shaft. 
     
     
       5. The aircraft powerplant of  claim 3 , wherein the rotating electrical connector is connected between the load cell and the propeller. 
     
     
       6. The aircraft powerplant of  claim 2 , wherein the load cell comprises a body and a plurality of strain gauges positioned substantially equidistantly around a circumference of the body. 
     
     
       7. The aircraft powerplant of  claim 6 , wherein the computing device is configured for determining the propeller thrust based on an average of measurements from the strain gauges. 
     
     
       8. The aircraft powerplant of  claim 6 , wherein the computing device is configured for determining the propeller thrust based on a calibration curve of voltage versus load. 
     
     
       9. The aircraft powerplant of  claim 2 , wherein the computing device is further configured for determining a 1P moment of the propeller based on the measurement. 
     
     
       10. A method for measuring propeller thrust, the method comprising:
 extracting energy from combustion gas in a gas turbine engine using a turbine section of the gas turbine engine; 
 converting the energy into rotary motion via a shaft mounted to the turbine section; 
 transferring the rotary motion to a propeller through a load cell coupled between the shaft and the propeller, the propeller configured for converting the rotary motion into propeller thrust; and 
 measuring the propeller thrust from the load cell as the propeller rotates. 
 
     
     
       11. The method of  claim 10 , wherein measuring the propeller thrust comprises:
 transmitting a measurement indicative of thrust from the load cell to a computing device; and 
 determining the propeller thrust in the computing device based on the measurement. 
 
     
     
       12. The method of  claim 11 , wherein transmitting the measurement indicative of thrust from the load cell to the computing device comprises transmitting the measurement through a rotating electrical connector coupled between the load cell and the computing device. 
     
     
       13. The method of  claim 11 , wherein transmitting a measurement indicative of thrust comprises transmitting measurements from a plurality of strain gauges positioned substantially equidistantly around a circumference of a body of the load cell. 
     
     
       14. The method of  claim 13 , wherein measuring the propeller thrust comprises averaging the measurements from the strain gauges. 
     
     
       15. The method of  claim 13 , wherein measuring the propeller thrust comprises determining the propeller thrust based on a calibration curve of voltage versus load associated with the strain gauges. 
     
     
       16. The method of  claim 10 , further comprising measuring a 1P moment of the propeller from the load cell as the propeller rotates. 
     
     
       17. The method of  claim 16 , wherein measuring a 1P moment comprises:
 transmitting a measurement indicative of 1P moment from the load cell to a computing device; and 
 determining the 1P moment in the computing device based on the measurement indicative of 1P moment.